Hi Mattyboy
I presume you live in the UK judging by the equipment you have, me too

I hear Belden cables are very good, I'm currently in the process of making my own power cables using Belden 83803 cable, furutech connectors and techflex sheathing. (just ordered)
I have a 4BSST along with the BP26(DA) and PMC OB1's.
I use
Van Den Hul cs122 (about £10 mtr new, cheaper on eBay second hand) with Milty banana plugs, This is quite a heavy duty 2.96 mm² / 12.5 AWG silver plated, double dialectic cable that has good high current capabilities and is flexible which helps, I like to use as short lengths as poss (2 mtr in my case). I bi-wire to my tweeter and midrange and have jumper cables double wired from the midrange connector to the bass.
I find this cable sounds nice and smooth, plenty of detail and sparkle with good attack and deep bass. I've tried some QED XT400 (£20 mtr) in a tri-wire configuration using WBT 0680 spades on the amp and QED airlock on the speakers, thinking that ought to do the trick. But it sounded really bright and thin to my ears which opened up the sound too much. It didn't have the sense of power and fullness that you get with CS122, so out it came and I reverted back to the van den hul.
I haven't got access to other cables for a comparison unfortunately, but I find the CS122 has the right balance and quality's to enable me many hours enjoying the music without a thought of how the sound could be better
PMC believe "as long as you can get enough copper between power amp and speakers, you don't need to worry about the minutiae of its design" ( HI-FI Choice, issue 292 EB1 review)
I emailed them about cable recommendations when I bought my kit, and they said:-
"cable reccommendations are notoriously difficult as all cables act rather like a crude tone control tilting the frequency balance to make the system sound either brighter i.e. more detailed, or warmer, less detailed.
Our experience with nordost cable in the past has not been a happy one and it wouldn't be our choice.
a more conventional cable for both interconnects and speaker would be preferable.
We use Van damme cables for our studio installations. It works well and doesn't have a ridiculous price tag!
We've used Chord and QED in the past and achieved good results.
I purchased a Bryston balanced interconnect at the time which the dealer sought from PMC. I was told Brystons cables originate from a British company that supplies to them (not sure if that's true) Upon receiving my interconnect I discovered that it was just a basic lead that uses professional microphone cable and basic plugs. I was charged £110 for 0.5 mtr which is way too much for what I got, so can't recommend them at that price.